On Fri, 1 Sep 2000, Van den Berghe Sven wrote:
>
> In my latest analyses, I've found that at low angles, my peaks are rather
> asymmetric, with a tail towards the low angle side. Since Rietveld programs
> fit the entire spectrum, this asymmetry is often a cause of reduced
> reliability of my refinements. I was wondering what causes this asymmetry.
> I'm using a Philips X'Pert Pro goniometer with programmable divergence and
> anti-scatter slits. I set these at a constant irradiated surface of 15mm,
> but reducing this to 5 mm does not change the asymmetry. The receiving slit
> is set at 0.05mm to reduce peak width.
This is due to the (axial plus equatorial) divergencies of the
primary plus secondary xray paths. Have a look at www.bgmn.de/ger.html
The influence of this divergencies enlarge for smaller Bragg angles.
J. Bergmann, Dresden
[EMAIL PROTECTED]
